One is connected to my routed D-link and second one (internal) to giga-swith.

I have internet in core (YouTube etc.) after disable firewall I can access admin page from external lan.

When im connecting from internal side i'm getting IP (192.168.80.129) I can ping to core (192.168.80.1) but I don't have internet(in DHCP settings there is no gate) ant I cant access admin page or shares (\\192.168.80.1\)

I don't think there is lan card issue, it looks like core doesn't allow me to access any thing from internal network,

On the core's orbiter, click on the "Advanced" button (I think I've got that right, the one with all the reset buttons at the bottom) and find "Network Settings" (again, I think I've got this right). If you're in the right place, you should see two buttons saying something along the lines of "Use Static" and "Use DHCP". Try clicking on the DHCP one, and see if that gives you any joy.